Film mode judder or flicker is an unwanted video effect caused when two fields that combine to make the frame are not identically matched, thus creating two different time-alternating pictures. A process termed telecine or 3:2 pulldown may introduce film mode judder when it converts film shot at 24 Hz (or frames per second) to an interlaced 60 Hz video signal.
The inverse process, aptly named inverse-telecine or inverse 3:2 pulldown, converts the interlaced video signal to a progressive scan video signal when a progressive scan television or other device identifies the interlaced signal as having originated as film. This later process is often termed film mode detection. If the television cannot identify the interlaced video signal's origin as film, other processes including motion adaptive deinterlacing (MAD) convert the interlaced video signal to a progressive scan signal.
The inverse-telecine process does not completely remove or eliminate the judder introduced during the telecine process.
Accordingly, a need remains for a film mode judder elimination circuit and method.